|
|
|
|
Home
Search |
Upcoming Seminars
FRIDAY, February 8, 2008
COMPUTATIONAL AND APPLIED MATHEMATICS PROSEMINAR
PSA 206 3:15 p.m.
Aaron Luttman, Bethany Lutheran College
"Inverse Problems for Botanical and Astronomical Image
Analysis"
ABSTRACT: Many image analysis problems are formulated as
inverse problems, where the goal is to minimize a particular
energy functional over some set of allowable functions. Two
such problems are image segmentation and image deblurring. In
botany it is useful to capture image data of leaves as they
fluoresce in the infra-red, and the goal is to segment the
videos or images into regions of fluorescence and non-
fluorescence. The botanical problem will be described as well
a variational technique with numerical methods for video
segmentation in this context.
Astronomical data measured from the ground is blurred as it
passes through the atmosphere, and this effect must be reversed
in order to analyze the data. This deblurring is formulated as
an inverse problem, and we present theoretical analysis and
numerical results demonstrating that Poisson negative log-
likelihood estimation can be used to reconstruct such
astronomical data when regularized using the total variation of
the reconstruction.
MONDAY, February 11, 2008
COLLOQUIUM (FACULTY CANDIDATE) PSA 206 3:30 p.m.
Luan Hoang, University of Minnesota
"Some Problems in Geophysical Fluid Dynamics"
ABSTRACT: We study mathematical problems in geophysical fluid
dynamics. The Navier-Stokes equations in thin domains are used
to model the motion of fluids in the atmosphere and oceans. The
domain considered here has depth of order \varepsilon as
\varepsilon \to 0. The velocity field is subject to the Navier
boundary conditions on the non-flat top and bottom boundaries.
Roughly speaking, we show that for appropriate forces, if the
H^1 norm of initial velocity is O(\varepsilon^{-\frac{1}{2}})
as \varepsilon \to 0, then there exists a unique strong solution
for all time. We also discuss similar results for Boussinesq
equations of the oceans which contain the additional unknown
temperature and salinity concentration. Our proofs rely on the
study of the dependence of the Stokes operator on \varepsilon,
and the non-linear estimate which has to deal with the non-
trivial contributions of the boundary integrals connected with
the boundary conditions.
This is a joint work with George Sell.
Refreshments will be served in PSA 206 at 3:15 p.m.
TUESDAY, February 12, 2008
APPLIED ANALYSIS AND PDE READING SEMINAR PSA 546 3:00 p.m.
For more information, contact Svetlana Roudenko.
WEDNESDAY, February 13, 2008
MATHEMATICA WORKSHOP ECA 225 3:00 p.m.
Joel Klein, Kernel Developer, Wolfram Research
"Mathematica 6 in Education and Research"
This talk illustrates capabilities in Mathematica 6 that are
directly applicable for use in teaching and research on campus.
Topics of this technical talk include:
* 2D and 3D visualization
* Dynamic interactivity
* On-demand scientific data
* Example-driven course materials
* Symbolic interface construction
* Practical and theoretical applications
Current users will benefit from seeing the many improvements
and new features of Mathematica 6
(http://www.wolfram.com/mathematica/newin6), but prior
knowledge of Mathematica is not required.
The workshop is open to the ASU community. There will be a
"questions and answers" session at the end of the workshop.
THURSDAY, February 14, 2008
COMPUTATIONAL AND APPLIED MATHEMATICS PROSEMINAR
PSA 206 12:15 p.m.
Rishu Saxena, Department of Mathematics and Statistics
"High-Order Edge Detection from Scattered Data" (Oral Exam)
ABSTRACT: Detection of edges in piecewise smooth functions is
important in many applications such as image processing,
computer vision and seismology. Unfortunately, most of the
algorithms available until recently are first order and depend
on external factors such as the choice of appropriate filters
and thresholds. Further, their use is mostly limited to digital
images. On the other hand, extensive research has been done for
high order methods in the Numerical Partial Differential
Equations community.
The polynomial annihilation edge detection method (Archibald,
Gelb and Yoon, 2005) was the first attempt to make edge
detection a high order venture from physical data. The method
has several advantages over already existing methods, the most
important being that it is applicable to multi-dimensional
scattered data. This talk discusses the polynomial annihilation
edge detection method and then expands it for several
applications, as needed not only in the field of image
processing, but also in a broad range of other applications
including determining edges in derivatives of functions for
post processing partial differential equations as well as
determining discontinuities in greater than three dimensions
which arise in stochastic partial differential equations. The
focus of this study is on functions that are continuous but not
smooth and are irregularly sampled.
FRIDAY, February 15, 2008
MATH BIO SEMINAR ECG G237 3:40 p.m.
Tom Andersen, University of Oslo, Norway
"The Stoichiometry of Autotroph-Herbivore Systems - A Gentle
Introduction"
ABSTRACT: Starting from the original Lotka-Volterra model,
biological realism will be introduced step by step until we
reach at stoichiometrically explicit autotroph-herbivore model
that is consistent with the principles of mass conservation and
with basic animal physiology. Consequences for qualitative
dynamics at each step will be illustrated by phase plane
diagrams and nullcline analysis. Finally, we will consider some
open issues arising for our current lack of knowledge about the
strategies and options herbivores have for disposing excessive
materials and conserving limiting ones.
|